“We know the right thing to do,” President Obama said about renewable energy at his press conference Tuesday. “We’ve known the right choice for a generation. The time has come to make that choice and act on what we know.…We have achieved more in two months for a clean energy economy than we have done in perhaps 30 years.”

Thirty years. Let’s see, that would be 1979, right? Hmmm… wasn’t that the year — yes, that was when Jimmy Carter finally got his Grand Energy Plan through Congress, setting us the road to corn ethanol, the Synthetic Fuels Corporation and a host of other harebrained schemes.

Carter Redux, that’s the only way to describe the Obama Administration’s approach to energy. After thirty years out of power, the purveyors of the Solar and Renewable Utopia are back. We’re going to develop windmills, make solar panels affordable, and redesign buildings so they use only half as much energy — in theory, at least. The subtext, of course, is this — we won’t have to deal with coal, nuclear or any of those other nasty technologies that aren’t “clean and renewable.”

So what’s wrong with this picture? Well, the problem is that thirty years hasn’t changed the laws of physics. Things like the intensity of sunlight or wind power keep intruding. Nuclear power has two million times the energy density of fossil fuels. Fossil fuels are again ten times as dense as wind and solar. Multiply it out and that comes to a factor of twenty million. How does this manifest itself? Well, in the amount of land that will be required to collect all that solar and wind energy before we can begin using it.

All this came home to me again the other night while I was watching a DVD of Thomas Friedman’s “Green is the New Red, White and Blue” special, which ran on the Discovery Channel. At one point, Friedman finds a hydrogen car running on fuel cells and producing zero emissions. The cars costs a million dollars to build but don’t worry, he says, mass production will improve that. Then he goes to a hydrogen filling station in California, run by Honda and asks them to fill ‘er up. “Where do you get the hydrogen,” he asks. The Honda officials show him a solar panel about a block long right next to the station. Friedman’s enthusiasm wanes, however, when he learns about the flimsiness of solar energy. “These solar panels,” he says, “measuring 700 square feet, take a week to generate enough hydrogen to fill one fuel tank.”

Anything solar immediately runs into the same problem. There just isn’t that much energy there to begin with. In January 2009 three leading solar researchers, writing in Scientific American, proposed that by 2050 American get all its electricity from solar panels in the Southwestern desert. All we would require would be 46,000 square miles — about one-third of New Mexico, the fifth largest state. Al Gore repeated this proposal before the Senate Energy Committee in February, although he managed to reduce the requirements to 10,000 square miles, based on the untested claims of Ausra, a California company that hasn’t yet built anything but in which he is probably investing. Vaporware doesn’t just apply to computers, you know.

Yet all this is being put into effect in California right now. With a renewable portfolio standard demanding 20 percent renewables by next year and 33 percent by 2020, just about anybody with rats on a treadmill can sell electricity to the state’s utilities right now and be guaranteed a profit. Right now fourteen thinly funded companies are furiously drawing up plans to fill the Mojave Desert with solar installations, knowing the utilities will have to buy anything they generate.

That’s why California Senator Dianne Feinstein announced last week that she is introducing a bill to set 600,000 acres of Bureau of Land Management holdings in the Mojave Desert off-limits to solar projects. “Such development would violate the spirit of what conservationists had intended when they donated much of the land to the public,” she said. “It would destroy the entire Mojave Desert ecosystem,” added David Myers, executive director of The Wildlands Conservancy, which originally dedicated some of the land to the BLM.

Hmmm…endangered species? Environmental impact? Didn’t anybody ever think of these things before? Yet such environmental objections are inevitable. A thermal solar station requires 50 square miles to generate the same 1000 megawatts (MW) you can get from a mile square coal or nuclear plant. And that’s only when the sun shines! A photovoltaic plant will require 75 square miles. A wind farm takes 125 square miles and then only generates electricity 30 percent of the times. To be assure of anything near constant output you probably have to cover 500 square miles in diverse locations. The Nature Conservancy — which is supporting nuclear — calls this “energy sprawl.” It’s a great term. I wish I’d thought of it myself.

Just to pile on, though, here’s another consideration. One of the biggest problems with solar panels is that they accumulate dust, dirt and sand, which reduce their efficiency by considerable amounts. Existing installations have to be washed down every few weeks with water. Has anybody thought of where in the middle of the desert you’re going to find enough water to wash down 10,000 square miles of solar panels?

The one path not being pursued by the Obama Administration, of course, is nuclear energy. That would be too easy. All we’d have to do is admit that the purveyors of “clean and renewable energy” are living in a fantasy world. Once that was done, we could employ current technology, use the existing electrical grid, and skip all the business of flagellating ourselves about all the harm we do to the planet. We could put tens of thousands of construction workers to work, cut through bureaucracy (we’d have to give up the five-year reviews by the Nuclear Regulatory Commission), and let Silicon Valley go back to building computers instead of thinking they can solve the world’s energy problems.

Granted, Susan Hockfield, president of MIT, who spoke at the press conference Monday afternoon, did say something about developing “safer and more efficient nuclear technologies,” but that’s always the way. Safe and acceptable nuclear energy is always somewhere over the horizon. In fact, the technology we’ve got now is already safe and efficient. We just have to use it. Energy Secretary Steven Chu spoke for the Administration two weeks ago, however, when he cancelled Yucca Mountain. The move wasn’t really that significant, since reprocessing nuclear fuel makes much more sense. (See “There Is No Such Thing as Nuclear Waste,” Wall Street Journal, March 13, 2009) But it speaks volumes about what to expect form the Obama Administration on nuclear power.

Jimmy Carter’s Presidency was brought down by his failure to deal with the energy problem. After four years of floundering around with oil price controls and “alternate energy” Carter was overwhelmed by world events.

Is the Obama Presidency headed down the same road? I wouldn’t bet against it.